<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Hello Extensions</title>
    <style>
        body {
            width: 500px;
            text-align: center;
        }
    </style>
</head>
<body>
    <h1>Hello Extensions - Postbird</h1>
</body>
<script>
    alert('test alert')
</script>
</html>